Controllers usually have only a physical user interface. For example, a light switch has a manual switch, which is usually implemented mechanically. Controllers are currently developed for remote control of an electronic device over a data transfer connection.
If the controller has a controlling computer, then the controllers required for device control are installable directly to the controlling computer from for example a diskette or a laser disc. This solution requires manual work, something that is not desirable in future automatically generated networks of devices and services, i.e. ad hoc networks. Network maintenance is also laborious.
On the other hand, solutions exist wherein the controller contains server software serving it. A usual Internet connection mechanism requires the TCP/IP protocol (Transmission Control Protocol/Internet Protocol). In addition, a Java virtual machine is often needed as a base for the user interface, since it enables portability of the user interface. Such a controller is too expensive to make, since the microprocessors comprised by it must possess a relatively high processing power.
For example Jini, developed by Sun, is a technology utilizing the Java programming language and enabling automatic generation of ad hoc networks. However, Jini is intended for relatively expensive devices, e.g. computers, laser printers, telephones and digital cameras, which include the necessary processing power. Registering a controller's user interface in an ad hoc network often requires running a Java programming language virtual machine in the controller. This is difficult to implement at a reasonable cost efficiency for simple controllers. However, it would be extremely desirable to be able to use the user interface of a controller over a data transfer connection, for example a wireless network or the Internet.
To summarize, known solutions are too expensive or difficult to maintain.